Calculations

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Transcript of Calculations

Addition, Subtraction, Multiplication, Division CALCULATIONS The Language of Calculations Mental Strategies INFORMAL & FORMAL Written Methods The things that will help! KEY FACTS Add Subtract Multiply Divide Mathematics JuniorsOctober 2012 total AND Sum of INCREASE more than PLUS ADDITION together + Minus LESS THAN difference TAKE AWAY decrease reduce _ fewer x times lots of groups of product multiple multiplication _ division groups of will each get shared average out of quotient divided by use KNOWN facts to help Make jottings Do it in the order that works best for you INFORMAL FORMAL CALCULATIONS

Our aims for the children at St. Monica’s

To have a secure knowledge of number facts and a good understanding of the 4 operations To use this knowledge to carry out calculations mentally To know when mental methods are notappropriate To have an efficient, reliable, written method of calculation for each operation Have a go at these word problems Your Turn! Mrs Tottle-Nugent will read out a Mental maths test. You get a limited time to respond and there's no going back!Good Luck!! Your Turn! We will show you a selection of calculationsTry to use a different method for each one.Try to use:a number linePartitioningA gridChunking!It's possible that the methods that you were taught or work best for you, are NOT THE SAME for your child. Your turn Times tables Number bonds Doubles Halves Divisibility rules Number linesPartitioningGrid methodChunkingUse near and adjust Column Addition Column Subtration Column Multiplication Short Division 5x4=20 20-4=5 20-5=4 4+4+4+4+4=20 5+5+5+5=20 and using knowledge of place value 5x40=200 4x50=200 200-50=4 200-40=5 40x50= 20000.5x4=25x0.4=20.4x0.5=0.2and so on..... If you know 4x5= 20 what else do you know? 2 - the last digit is 0,2,4,6 or 83- the sum of the digits is divisible by 34- the last 2 digits are divisible by 45 - the last digit is 5 or 06 - It is divisible by both 2 & 37 - Check a known near multiple of 78 - Half of it is divisible by 4 ORthe last 3 digits are divisible by 89 - the sum of the digits is divisible by 910 - the last digit is 0 Divisibility Rules Know corresponding facts